Fibre Channel is a well known standard for network communications. It is generally used for applications where high data transmission rates and high reliability are necessary, such as storage networks. Fibre channel systems are usually based on one of three topologies—point to point, arbitrated loop and switched fabric. For each topology there exist standard initialization and messaging procedures which various devices connected to the network can use to announce their presence to other devices, determine what other devices are present in the network, and determine when a device enters or exits the network. In the point to point and arbitrated loop topologies, these procedures may be performed by the devices themselves. In the switched fabric topology, these procedures may be at least partially performed by the network fabric—i.e., various switches or servers that are considered to be part of the network itself and not devices communicating with the network.
Ethernet is a network communication standard traditionally used for applications for which the data transmission rate and reliability requirements are not as high as they are for Fibre Channel applications. For example, Ethernet is often used as a base layer for TCP/IP networks, which are in turn used for Internet networking. However, recent developments have brought about Ethernet technology featuring data transmission rates and reliability similar to those of Fibre Channel. An example is the converged enhanced Ethernet (CEE) currently being developed at the IEEE standards body.
Since Ethernet is very prevalent, there have been suggestions to move applications that traditionally rely on Fibre Channel (such as, for example, storage networking) to CEE or other types of Ethernet networks. This would save resources as it would remove the necessity of building and supporting two separate networks in an organization (i.e., a Fibre Channel network for storage and an Ethernet network for Internet access, computer to computer communications, etc).
However, changing existing Fibre Channel applications to Ethernet may require that existing networking devices such as, for example, host bus adapters (HBAs) be completely redesigned to use Ethernet or use other suboptimal protocols such as Internet SCSI (iSCSI). Since existing Fibre Channel HBAs incorporate many years worth of innovation, it may not be cost efficient to completely redesign these devices.
One suggested scheme of switching from Fibre Channel to Ethernet without completely redesigning existing HBAs is to use gateways. More specifically, Fibre Channel over Ethernet (FCoE) gateways can be used to connect a Fibre Channel component to an Ethernet network. An FCoE gateway may be a stand alone device which is connected to the Fibre Channel component through a Fibre Channel link. The gateway may also be connected to an Ethernet network and may thus combine an existing Fibre Channel based HBA with an Ethernet network. However, this approach is not considered optimal as the requirement of using additional standalone devices (i.e., FCoE gateways) would add significant costs and complexity to the resulting networks. Furthermore, this would not completely eliminate the necessity for Fibre Channel infrastructure, because a Fibre Channel connection between the gateway and the HBA would still be necessary.
Therefore, there is a need for creating an end to end CEE (or other Ethernet) high speed network that utilizes the technology of existing Fibre Channel HBAs to a great extent.